1. Field of the Invention
The present disclosure relates to the assembly of bladed disks. More specifically, the present disclosure relates to assembly methods and devices that aid in the installation of shrouded or other high aspect ratio blades in a compressor or turbine disk of aero or land based gas turbine engines.
2. Description of Related Art
Gas turbine engine blades have roots that are installed into broached slots in the outer diameter of a disk. The blades have a curved airfoil portion extending radially outward from the blade root and longer blades include a shroud on the distal end of the airfoil portion. When the blades are installed in the disk, the shrouds on the ends of the blades interlock with the shrouds of adjacent blades at a z-notch, which increases damping and thereby reduces blade dynamic response. The z-notches also restrict leakage flow around the blades. But, the shrouded blade design makes the blades difficult to install because they are designed to twist when being seated into the broached slots to provide loading on the shroud dampers.
The installation of shrouded blades in a disk is traditionally accomplished by manually hammering the roots of each of the blades into the disk with a non metallic mallet. The roots of the blades are seated in the disk slots by hammering them down into the broached slots, which may be configured as a fir tree shape. The blades are gradually driven into the broached slots in a circular manner by making multiple trips around a table/wheel that holds the disk in place while the blades are being installed. This method of manual blade installation is relatively time consuming and can cause impact damage to the blade root and/or broached disk slot. Root seal strip materials may require additional effort and force.
Accordingly, there is a need for a device to install unshrouded, shrouded or high aspect ratio blades into a disk that can improve the current assembly process. For example, a novel installation device that installs blades in a more controlled manner that prevents jamming and damaging of the blade roots or broached slots is needed. An improved installation method is also needed that is faster and does not require the repetitive manual hammering against the blade roots.